Combined television and radio receiving system



Feb 18, 1941. R. H. MAN s oN 2,232,399

COMBINED TELEVISION AND RADIO RECEIVING SYSTEM Filed Dec. 13, 1938DDEDEIBDDEI INVENTOR.

9/7) H. NH $0/v ATTORNEY.

Patented F eb. 18, 1941 PATENT OFFICE.

ooivmmnn TELEVISION AND RADIO RECEIVING SYSTEM Ray H. Manson, Rochester,N. Y., assignor to The Stromberg-Carlson Telephone ManufacturingCompany, Rochester, N. Y., a corporation of New York ApplicationDecember 13, 1938, Serial No. 245,466

3 Claims.

This invention relates to a combined television and radio receivingsystem.

In a system of this kind, it is desirable to house the televisionreceiving apparatus and the radio receiving apparatus in the samecabinet. However, it hasbeen discovered that the sound pressurecomponents developed within the cabinet by the inner surface of thediaphragm of a cone-type loud speaker, mechanically vibrate the elementsin the cathode-ray tube and the electrical circuits forming a part ofthe television receiving apparatus, in a manner tending to cause imagedistortion. Present cathode-ray tubes of a size sufficient to givesatisfactory television images, are of such length that if these tubesare mounted horizontally in cabinets, thecabinet-s must be of such depththat they will be necessarily bulky and. will occupy an inordinateamount of space in any room. The necessarily large space within thecabinet and especially the increased depth of the cabinet from the frontto the rear thereof, tends to develop large cavity resonance, whichdistorts the signal reproduced by the loud speaker, causing anobjectionable sound effect known in the art as boominess.

In accordance with the present invention, there is provided a combinedtelevision and radioreceiving system which is compactly housed in agenerally triangular cabinet with the cathode-ray tube having itsprincipal axis extending horizontally in the cabinet so that its viewingend is visible through an opening in the front of the cabinet, and sothat its small end projects into the apex of the cabinet opposite saidfront whereby the size of the cavity in the cabinet is reduced andwhereby means can be introduced for preventing the radio receiver fromdisturbing the cathode ray tube.

Another feature of the invention relates to a 40 cabinet adapted to bepositioned in a corner of a room whereby the front of the cabinetextends across the corner and thereby limits the radiation of the loud.speaker to a radiation angle of approximately 90 as distinguished from180 as is 5 the case where a rectangular cabinet is placed with its backagainst a side wall of a room. This restricted radiation affords aneffectively stronger acoustic signal at the ear of the listener with agiven signal output, than where the same signal is distributed through aradiation angle of 180.

These and other features will appear from the detailed description andclaims when taken with the drawing in which:

Figs. 1 and 2 are respectively front and top views of a combinedtelevision and radio receiving system made in accordance with thepresent invention; and

Fig. 3 is a vertical section taken on substan-{- cated as indicated atB, 1 and 8. One of the vertical cabinet walls such as 9, which isconvenient ly referred to as the front, has provided therein, twoopenings I0 and I I. In the upper part of the cabinet there ishorizontally mounted, a cathode ray tube 12 having its large or viewingend l3 visible through the opening Ill. The reduced end or base I4 ofthe cathode ray tube extends toward the apex of the cabinet directlyopposite the front thereof, the depth of the cabinet between thelast-mentioned parts thereof being approximately equal to the length ofsaid tube. A shield I5 encloses the sides of this tube to prevent thescattering of the glass envelope of the tube in the event that the tubeis shattered. The synchronizing, amplifying and control apparatus V forthe cathode ray tube is preferably mounted on a shelf ll.

A second horizontal shelf [8 supports the radio receiving apparatus Rincluding the various amplifying and demodulating and audio output.stages which function to translate and amplify incoming audio signalsfor both the television and the broadcast programs and operate a loudspeaker I9 preferably of the cone diaphragm type. A series of controlknobs 20 located at the front of the cabinet adjust the amplifying andcontrol apparatus. A sufficient number of push buttons 2| are providedin the front of the cabinet to operate channel selecting circuits fortuning the various television video and associated audio channels. Alsopush buttons 22 are provided for selecting any one of a number ofpre-set standard broadcast station channels, and a dial 23 with pointer24 are provided for tuning standard broadcast and short wave stations byhand (manually). The radio receiving and loud speaker portion of thesystem need not be further described since they can be of theconventional type. The diaphragm of the loud speaker is mounted directlybehind the opening II in the front of the cabinet so that soundsgenerated by the front of the diaphragm are transmitted through thisopening into the room wherein the apparatus is used. The rear surface ofthe diaphragm of the cone of this typealso generates sound whichdevelops sound pressure components Within the interior of the cabinet.Such componentstend to be exaggerated by the cavity resonance of thecabinet.

In accordance with the present invention, the shelf [8 tends to preventthese components, which would otherwise disturb the operation of thecathode ray tube, from reaching the upper compartment of the cabinet. Asa further precaution against this type of disturbance the rear surfaceof the diaphragm communicates with a circuitous passageway 25 which ispreferably lined with a sound damping material so that the major portionof the sound generated at the rear surface of the diaphragm isdissipated and thereby further reduces any tendency for the soundpressures developed within the cavity fromreaching the cathode ray tube.

It will be appreciated that since the cabinet is generally triangular inhorizontal crosssection, it may be placed in the corner of a room whereit occupies a minimum amount of useful space. Furthermore, some cornerof every room is usually the darkest portion thereof, or else is themost readily shielded from light originating from a window. In additionsuch a triangular cabinet, when placed in the corner of a room has thefurther advantage that it restricts the area of sound radiation from theloud speaker and therefore, the efficiency of the loud speaker appearsto be greatly enhanced.

What I claim is:

1. In a structure of the class described, a cabinet generally triangularin horizontal section, said cabinet having an opening in one of itssides, a horizontally mounted cathode ray tube having its large endadjacent said opening in a position to be visible therethrough andhaving its small end projecting toward the apex of said cabinet oppositesaid side whereby the principal axis of said tube extends in a generallyhorizontal direction, the depth of said cabinet from said side to saidapex being such that the small end of said tube is located adjacent saidapex, apparatus to operate said tube, a loud speaker having a conetypediaphragm and apparatus for actuating the same supported within saidcabinet, the principal axis of said cone diaphragm extending in agenerally horizontal direction and means for absorbing the major portionof a sound pressure component generated by said loud speaker within saidcabinet whereby said tube is substantially undisturbed by saidcomponent.

2. In a structure of the class described, a cabinet generally triangularin horizontal section, said cabinet having an opening in one of itssides, a horizontally mounted cathode ray tube having its large endadjacent said opening in a position to be visible therethrough andhaving its small end projecting toward the apex of said cabinet oppositesaid side whereby the principal axis of said tube extends in a generallyhorizontal direction, the depth of said cabinet from said side to saidapex being such that the small end of said tube is located adjacent saidapex, an apparatus to operate said tube, a loud speaker having acone-type diaphragm and apparatus for actuating the same supportedwithin said cabinet with the principal axis of said cone diaphragmextending in a generally horizontal direction, and means including acircuitous sound damping path for absorbing the major portion of a soundpressure component generated by said loud speaker within said cabinetwhereby said tube is substantially free from acoustical disturbances.

3. In a combined radio and television receiver. a cabinet generallytriangular in horizontal crosssection, said cabinet having an opening inthe center of one of its sides adjacent the upper end thereof, ahorizontally mounted cathode ray tube having its large end adjacent saidopening in a position to be visible therethrough and having its smallend projecting toward the apex of said cabinet opposite said side, thedepth of said cabinet from said side to said apex being only slightlygreater than the length of said tube, said cabinet having a secondopening spaced from and disposed below said first mentioned opening,control apparatus related to said cathode ray tube, a loud speakerincluding a cone shaped diaphragm positioned in the lower portion ofsaid cabinet with the principal axis of said cone extending in agenerally horizontal direction, said diaphragm being mounted adjacentsaid opening with one of its surfaces serving to project sound throughsaid second opening, and means for preventing a sound pressure componentdeveloped within said cabinet by said loud speaker from disturbing saidcontrol apparatus.

RAY H. lVLANSON.

